Comprehensive laboratory and field testing of cavity ring-down spectroscopy analyzers measuring H2O, CO2, CH4 and CO
- 1Laboratoire des Sciences du Climat et l'Environnement (LSCE/IPSL), CNRS-CEA-UVSQ, Centre d'Etudes Orme des Merisiers, Gif-sur-Yvette, France
- 2Picarro Inc., 3105 Patrick Henry Drive, Santa Clara, CA, USA
- anow at: Air Normand, 3 Place de la Pomme d'Or, 76000 Rouen, France
- bnow at: Laboratoire National de métrologie et d'essais, (LNE), 1 rue Gaston Boissier, 75724 Paris CEDEX 15, France
Abstract. To develop an accurate measurement network of greenhouse gases, instruments in the field need to be stable and precise and thus require infrequent calibrations and a low consumption of consumables. For about 10 years, cavity ring-down spectroscopy (CRDS) analyzers have been available that meet these stringent requirements for precision and stability. Here, we present the results of tests of CRDS instruments in the laboratory (47 instruments) and in the field (15 instruments). The precision and stability of the measurements are studied. We demonstrate that, thanks to rigorous testing, newer models generally perform better than older models, especially in terms of reproducibility between instruments. In the field, we see the importance of individual diagnostics during the installation phase, and we show the value of calibration and target gases that assess the quality of the data. Finally, we formulate recommendations for use of these analyzers in the field.